Polyolefin catalyst for polymerization of propylene and a method of making and using thereof

ABSTRACT

A method of forming a polyolefin catalyst component which includes chlorinating magnesium ethoxide, and then treating the product first with an electron donor, particularly diethyl phthalate or di-isobutyl phthalate, at a relatively low donor level, and then second with a titanating agent, such as titanium tetrachloride, to produce a catalyst component. The catalyst component is activated with an aluminum alkyl cocatalyst. An external electron donor, such as an organosilane compound, is added for stereoselectivity control. The activated catalyst is used in the polymerization of olefins, particularly propylene, to obtain a polymer product with a broad molecular weight distribution.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a catalyst, a method of making saidcatalyst and a process for polymerizing α-olefins with said catalyst.The catalyst precursor is synthesized using metal alkoxides or metaldialkyls, a halogenating agent, an electron donor compound and atitanating agent. The catalyst precursor is activated with an aluminumalkyl and is used, optionally with a stereoselectivity control agent, topolymerize α-olefins, particularly propylene.

2. Description of the Related Art

Ziegler-Natta catalysts, their general methods of making, and subsequentuse for polymerization of olefins, are well known in the art. However,while much is known about Ziegler-Natta catalysts, improvements incatalyst performance and in their ability to produce polyolefins havingcertain properties are desirable.

U.S. Pat. No. 4,472,521, issued Sep. 18, 1984 to Band, discloses apolyolefin catalyst made by contacting a Mg(OR)₂ and/or Mn(OR)₂ withtitanium tetrachloride, then with a titanium tetrachloride halogenatingagent, and then with an electron donor.

U.S. Pat. No. 4,673,661, issued Jun. 16, 1987, and U.S. Pat. No.4,724,255, issued Feb. 9, 1988, both to Lofgren et al. disclose apolyolefin catalyst component made by chlorinating a magnesium alkylwhich is then contacted with titanium tetrachloride, a Lewis base, andthen at least once with titanium tetrachloride in the absence of a Lewisbase. Lofgren et al. teach the criticality of an electron donor at thefirst titanium tetrachloride treatment step and further teach away fromthe presence of an electron donor at subsequent titanation steps.

U.S. Pat. No. 4,855,271, issued Aug. 8, 1989, and U.S. Pat. No.4,937,300, both to McDaniel et al. disclose a polyolefin catalystderived from alumina impregnated with magnesium alkoxide, which issubsequently contacted with a lower order alcohol, chlorinated withsilicon tetrachloride, and subsequently etched with a titaniumtetrachloride.

U.S. Pat. No. 5,075,270, issued Dec. 24, 1991 to Brun et al. discloses apolyolefin catalyst made by reacting a magnesium alkoxide with analuminosiloxane derivative, which product is then chlorinated withsilicone tetrachloride, followed by transition metal treatment withtitanium tetrachloride, with an electron donor optionally associatedwith the transition metal.

Even with these prior art methods there is another need for polyolefincatalysts having improved performance. These and other needs in the artwill become apparent to those of skill in the art upon review of thispatent specification.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide for improvedpolyolefin catalysts, methods of their making, and methods ofpolymerizing olefins, particularly propylene.

It is another object of the present invention to provide for polyolefincatalysts having improved performance.

These and other objects of the present invention will become apparent tothose of skill in the art upon review of this patent specification.

According to one embodiment of the present invention there is provided aprocess for preparing a polyolefin catalyst precursor. The method firstincludes contacting a metal alkoxide, such as magnesium ethoxide, or ametal dialkyl with a halogenating agent, such as titanium tetrachloride,to form (A) an alkoxy metal halide (or an alkyl metal halide), metaldihalide and complexes thereof. These compounds and complexes are formedin a slurry with a hydrocarbon solvent. An electron donor, such as analkyl phthalate compound, was added and the mixture was heated. Theslurry was cooled and the solid separated and washed. The solid wasagain treated with titanium tetrachloride in a slurry and heated. Thesolid was separated, washed and dried.

DETAILED DESCRIPTION OF THE INVENTION

The method of the present invention for making a catalyst componentgenerally includes the steps of halogenating a metal alkoxide, metaldialkyl or metal alkoxyhalide, introducing an electron donor which isthen followed by at least one subsequent titanation treatment.

Metal alkoxides, metal dialkyls or metal alkoxyhalides suitable for usein the present invention include any that which when utilized in thepresent invention will yield a suitable polyolefin catalyst. Preferredmetal alkoxides, metal dialkyls and metal alkoxyhalides include thosewith metal from Group IIA and VIIB. Metal alkoxide, metal dialkyls andmetal alkoxyhalides are preferred in that order. Most preferred is amagnesium alkoxide.

The general formula of the metal alkoxide, metal dialkyl or metalalkoxyhalide is M(OR)₂, MR₂, or M(OR)X responsively, wherein M is anysuitable metal, and R is a hydrocarbyl or substituted hydrocarbyl moietyhaving from 1 to 20 carbon atoms and X is a halogen. M is preferably aGroup IIA and VIIB metal, most preferably magnesium; R is preferably ahydrocarbyl or substituted hydrocarbyl moiety having from 2 to 10 carbonatoms, and more preferably R is a hydrocarbyl or substituted hydrocarbylmoiety having from 2 to 6 carbon atoms, and most preferably, R has from2 to 4 carbon atoms. X is preferably chlorine.

Examples of preferred species of metal alkoxides include magnesiumethoxide, magnesium butoxide, manganese ethoxide, and manganesebutoxide. The most preferred metal alkoxide species is magnesiumethoxide. While not required, it is preferred that the magnesium alkylsbe soluble in a hydrocarbon solvent. Examples of suitable magnesiumdialkyls include dibutyl magnesium and butylethyl magnesium.

Halogenating agents are those compounds which can cause replacement ofthe alkoxide group(s) or the alkyl groups with a halogen. Halogenatingagents useful in the halogenating step for halogenating the metalalkoxide, metal dialkyl or metal alkoxyhalide include any halogenatingagent which when utilized in the present invention will yield a suitablepolyolefin catalyst. Chlorides are the preferred halogenating agents.

Group III, Group IV and Group V halides may be employed, as may hydrogenhalides, or the halogens themselves. Specific examples of preferredhalogenating agents are BCl₃, AlCl₃, CCl₄, SiCl₄, TiCl₄, ZrCl₄, VOCl₄,VO₂ Cl, CrO₂ Cl, SbCl₅, POCl₂, PCl₅, and HfCl₄. More preferredhalogenating agents are SiCl₄ and TiCl₄, with the most preferredhalogenating agent being TiCl₄. Other halogenating agents include alkylhalo silanes of the formula R_(x) SiX.sub.(4-x), wherein X is a halogen,R is a substituted or unsubstituted hydrocarbyl having 1 to 20 carbonatoms, and X is a halogen.

This initial halogenating of the metal alkoxide or metal dialkylcompound is generally conducted in a hydrocarbon solvent under an inertatmosphere. Non-limiting examples of suitable solvents include toluene,heptane, hexane, octane and the like. The preferred solvents are tolueneand heptane.

In this halogenating step, the mole ratio of metal alkoxide or metaldialkyl to halogenating agent is generally in the range of about 6:1 toabout 1:3, preferably in the range of about 3:1 to about 1:2, and morepreferably in the range of about 2:1 to about 1:2.

This initial halogenating step is generally carried out at a temperaturein the range of about 0° C. to about 100° C., a pressure in the range ofabout 15 psi, to about 50 psi, and for a reaction time in the range ofabout 0.5 to about 4 hours. Preferably, the halogenating step is carriedout at a temperature in the range of about 20° C. to about 90° C., apressure in the range of about 15 psi to about 30 psi, and for areaction time in the range of about 1 hour to about 2 hours.

Once the halogenating step is carried out and the metal alkoxide, metaldialkyl or metal alkoxyhalide is halogenated, the precipitated solidhalide product is recovered by any suitable method, and washed with ahydrocarbon solvent to remove any reactants from the halogenating step.

An internal electron donor is then added to the metal halide. Internalelectron donors for use in the preparation of polyolefin catalysts arewell known, and any suitable internal electron donor may be utilized inthe present invention which will provide a suitable catalyst. Electrondonors are Lewis bases and may be an organic compound of oxygen,nitrogen, phosphorus, or sulfur which can donate an electron pair to thecatalyst.

The electron donor may be a monofunctional or polyfunctional compound,advantageously selected from among the aliphatic or aromatic carboxylicacids and their alkyl esters, the aliphatic or cyclic ethers, ketones,vinyl esters, acryl derivatives, particularly alkyl acrylates ormethacrylates and silanes. Preferably, the electron donor of the presentinvention is an alkyl phthalate, and, more preferably, is a dialkylphthalate. Specific examples of a suitable electron donor are diethylphthalate (DEP) and di-isobutyl phthalate (DIBP). The amount of electrondonor utilized will generally vary over the range of about 0.1 to about1.0 mmol phthalate/ g Mg(OEt)₂, preferably from about 0.1 to 0.2 mmolphthalate/ g Mg(OEt)₂.

The contact time for addition of the electron donor ranges from about0.5 hours to about 4 hours, preferably from about 1 hour to about 2hours. Suitable temperatures for the addition of the electron donor stepare generally in the range of about 20° C. to about 90° C., withsuitable pressures in the range of about 15 psi to about 50 psi.

The titanation step is generally carried out by first slurrying theintermediate product. Nonlimiting examples of suitable hydrocarbonsolvent include heptane, hexane, toluene, octane and the like.

The titanating agent is preferably a tetra-substituted titanium compoundwith all four substituents being the same and the substituents being ahalide, an alkoxide or phenoxide with 2 to 10 carbon atoms. The samecompound used as a halogenating agent may be used as a titanating agent.The most preferred titanating agent is TiCl₄.

In general, the amount of titanium tetrachloride utilized will generallybe in the range of about 0.5 to about 5 equivalents, preferably in therange of about 1 to about 4, and most preferably in the range about 1.5to about 2.5 equivalents (based on the magnesium compound).

Following the addition of the titanium tetrachloride, the slurry is thenfurther heated to a temperature in the range of about 90° C. to about150° C., preferably to a temperature in the range of about 100° C. toabout 125° C. The slurry is held in this elevated temperature for aholding period in the range of about 0.5 hours to about 8 hours,preferably for a holding period in the range of about 1 hour to about 4hours. Subsequently, the solid precipitate is recovered by any suitablerecovery technique and washed with a hydrocarbon solvent.

The method of using the catalyst component in the polymerization ofolefins generally include combining the catalyst component with acocatalyst to form an active catalyst, adding an external electron donorfor stereoselectivity control, optionally prepolymerizing the catalystwith a small amount of monomer, introducing the catalyst into apolymerization reaction zone containing the monomer.

The cocatalyst component used to activate the catalyst component is anorganoaluminum cocatalyst component to form a catalyst system suitablefor the polymerization of olefins. Typically, the cocatalysts which areused together with the transition metal containing catalyst componentare organometallic compounds of Group Ia, IIa, and IIIa metals, such asaluminum alkyls. The aluminum alkyl cocatalyst is of the general formulaAlR'₃ where R' is an alkyl of from 1-8 carbon atoms or a halogen and R'may be the same or different with at least one R' being an alkyl.Examples of aluminum alkyls are trimethyl aluminum (TMA), triethylaluminum (TEAl), triisobutyl aluminum (TiBAl) and diethyl aluminumchloride (DEAC). The preferred aluminum alkyl is TEAl.

External donors which may be utilized in the preparation of a catalystaccording to the present invention include organosilane compounds suchas alkoxysilanes of general formula SiR_(m) (OR')_(4-m) where R isselected from the group consisting of an alkyl group, a cycloalkylgroup, an aryl group and a vinyl group; R' is an alkyl group; and m is0-3, wherein R may be identical with R'; when m is 0, 1 or 2, the R'groups may be identical or different; and when m is 2 or 3, the R groupsmay be identical or different

Preferably, the external donor of the present invention is selected froma silane compound of the following formula: ##STR1## wherein R₁ and R₄are both an alkyl or cycloalkyl group containing a primary, secondary ortertiary carbon atom attached to the silicon, R₁ and R₄ being the sameor different; R₂ and R₃ are alkyl or aryl groups. In a preferredembodiment, R₁, is a alkyl or cycloalkyl of 1-6 carbon atoms, preferablymethyl, isopropyl, cyclopentyl, cyclohexyl or t-butyl; R₂ and R₃ aremethyl, ethyl, propyl, or butyl groups and not necessarily the same; andR₄ is also an alkyl or cycloalkyl of 1-6 carbon atoms, preferablymethyl, isopropyl, cyclopentyl, cyclohexyl or t-butyl. Specific externaldonors are cyclohexylmethyldimethoxy silane (CMDS),diisopropyldimethoxysilane (DIDS) cyclohexylisopropyl dimethoxysilane(CIDS), dicyclopentyldimethoxysilane (CPDS) or di-t-butyldimethoxysilane (DTDS), the most preferred being CPDS.

Generally, a prepolymerization process is effected by contacting a smallamount of monomer with the catalyst after the catalyst has beencontacted with the electron donor. A prepolymerization process isdescribed in U.S. Pat. Nos. 4,767,735, 4,927,797 and 5,122,583, herebyincorporated by reference.

The catalysts of the present invention can be used for thepolymerization of any type of α-olefins. For example, the presentcatalyst is useful for catalyzing ethylene, propylene, butylene,pentene, hexene, 4-methylpentene and other α-alkenes having at least 2carbon atoms, and also for mixtures thereof. Preferably, the catalystsof the present invention are utilized for the polymerization ofpropylene to produce polypropylene.

EXAMPLES

In the following Examples, catalysts have been synthesized frommagnesium ethoxide that had been chlorinated with titaniumtetrachloride. The resulting compound was treated with titaniumtetrachloride to produce a catalyst.

Treatment of magnesium ethoxide with titanium tetrachloride gives acatalyst which allows the production of broad molecular weightpolypropylene.

All reactions were carried under a nitrogen atmosphere using standardSchlenk and cannula techniques. Ti analysis was performed byspectrophotographic determination of the peroxide complex. The Mganalysis was performed by EDTA titration and Cl analysis by AgNO₃titration.

Mg(OEt)₂ (20 g, 0.176 mol) was slurried in 160 mL toluene and heated to90° C. To the stirred slurry, was added 40 mL (69.2 g, 0.364 mol) TiCl₄.The internal donor was added and the reaction mixture was heated to 115°C. for 2 h. The slurry was allowed to settle and cool to 90° C.,whereupon the supernatant liquid was removed by cannula and the solidwashed two times with 200 mL portions of toluene at 90° C. The solid wasagain slurried in 160 mL toluene and treated with 40 mL TiCl₄ at 90° Cas previously described. The reaction mixture was then heated to 115° C.for 2 h. Upon completion of the reaction, the slurry was cooled to 40°C. and the supernatant liquid removed. The solid was then washed sixtimes with 200 mL portions of heptane at 40° C. The washed solid wasthen dried in vacuo for 60 minutes at 50° C.

All polymerizations were carried out using the conditions described inTable 1. A 2 liter autoclave was charged with 1.4 liters of liquidpropylene and 16 mmol H₂. To this was charged 10 mg catalyst, 10 mmoltriethyl aluminum ("TEAL") and 0.1 mmol electron donor. The mixture washeated to 70° C. and maintained for 60 minutes. Polymerization wasquenched by venting propylene and exposure to air. The polymer was thendried at 60° C. Molecular weight was determined by gel permeationchromatography (GPC).

                                      TABLE 1                                     __________________________________________________________________________    Polymerization Data for Laboratory Catalysts                                        Yd.                                                                              BD MF                                                                Ex.                                                                             Donor                                                                             (g)                                                                              (g/cc)                                                                           (g/10 min)                                                                         % XS                                                                             M.sub.n                                                                           M.sub.w                                                                           D  D' Comments                                    __________________________________________________________________________    1 CMDS                                                                              100                                                                              0.37                                                                             4.40 2.76                                                                             49418                                                                             342298                                                                            6.93                                                                             3.49                                                                             100% DNBP.sup.a                             1'                                                                              CPDS                                                                              115                                                                              0.40                                                                             1.40 2.47                                                                             60964                                                                             490554                                                                            8.05                                                                             3.51                                                                             100% DNBP                                   2 CMDS                                                                              100                                                                              0.39                                                                             11.80                                                                              6.78                                                                             36993                                                                             282859                                                                            7.65                                                                             3.89                                                                              10% DNBP                                   2'                                                                              CPDS                                                                              116                                                                              0.41                                                                             7.00 6.18                                                                             39042                                                                             337369                                                                            8.64                                                                             3.96                                                                              10% DNBP                                   3 CMDS                                                                              140                                                                              0.38                                                                             9.40 5.58                                                                             39993                                                                             280935                                                                            7.02                                                                             3.69                                                                              20% DNBP                                   3'                                                                              CPDS                                                                              150                                                                              0.38                                                                             5.20 4.51                                                                             40648                                                                             326827                                                                            8.04                                                                             3.80                                                                              20% DNBP                                   4 CMDS                                                                              125                                                                              0.40                                                                             12.40                                                                              6.43                                                                             29551                                                                             280654                                                                            9.50                                                                             4.09                                                                              10% DEP                                    4'                                                                              CPDS                                                                              136                                                                              0.41                                                                             5.60 5.98                                                                             32957                                                                             339663                                                                            10.31                                                                            4.15                                                                              10% DEP                                    5 CMDS                                                                               58                                                                              0.38                                                                             10.50                                                                              7.06                                                                             29707                                                                             273191                                                                            9.20                                                                             4.04                                                                              20% DEP                                    5'                                                                              CPDS                                                                              105                                                                              0.42                                                                             5.60 5.34                                                                             31000                                                                             328987                                                                            10.61                                                                            3.97                                                                              20% DEP                                    6 CMDS                                                                               82                                                                              0.36                                                                             3.80 2.87                                                                             47997                                                                             332996                                                                            6.94                                                                             3.1                                                                              100% DEP                                    6'                                                                              CPDS                                                                               98                                                                              0.36                                                                             1.70 2.44                                                                             52382                                                                             386269                                                                            7.37                                                                             2.9                                                                              100% DEP                                    7 CMDS                                                                              100                                                                              0.41                                                                             10.70                                                                              7.86                                                                             26683                                                                             266472                                                                            9.99                                                                             4.03                                                                              10% DIBP                                   7'                                                                              CPDS                                                                              140                                                                              0.41                                                                             7.00 6.62                                                                             30246                                                                             307558                                                                            10.17                                                                            4.11                                                                              10% DIBP                                   8 CMDS                                                                               94                                                                              0.38                                                                             3.60 1.24                                                                             48455                                                                             360514                                                                            7.44                                                                             3.46                                                                             100% DIBP                                   8'                                                                              CPDS                                                                              112                                                                              0.41                                                                             1.30 2.16                                                                             63201                                                                             529919                                                                            8.38                                                                             3.50                                                                             100% DIBP                                   __________________________________________________________________________     Conditions: liquid propylene, 70° C., triethylaluminum cocatalyst,     Al/Ti = 200, Al/Si = 10, H.sub.2 = 16 mmol                                    .sup.a 100% is equivalent to 1 mmol phthalate/g Mg(OEt).sub.2            

The results above demonstrate that use of DEP or DIBP as an electrondonor in the synthesis of a catalyst precursor produces a catalyst whichin the polymerization of propylene yields a polymer with a relativebroad molecular weight distribution. Furthermore, using a lesser amountof DEP or DIBP electron donor increases the molecular weightdistribution to a greater extent than reducing the amount of DNBPelectron donor.

As the data above demonstrates, certain external electron donors incombination with the specific catalyst component containing certaininternal electron donor produces relatively small amounts of xylenesolubles and a relatively broad molecular weight distribution. Thiseffect is especially evident when CPDS is the external electron donor.As shown in the Examples and Table 1 above, xylene solubles aregenerally significantly lower and the molecular weight distribution issignificantly broader for the combination of CPDS as the externalelectron donor with the catalyst component containing DEP or DIBP as theelectron donor. In fact, the Examples for polypropylene having thebroadest molecular weight distribution (Examples 4 and 7) are for thecombination of CPDS and 10% of either DEP or DIBP. In addition, the useof CPDS as the external electron donor results in increased activity andlower xylene solubles over the combination of the other electron donorwith the catalyst component.

While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims he construed as encompassing all thefeatures of patentable novelty which reside in the present invention,including all features which would be treated and equivalents thereof bythose skilled in the art which this invention pertains.

We claim:
 1. A process of making a catalyst comprising:a) selecting acatalyst component for the polymerization of propylene wherein thecatalyst component comprises:(1) the reaction product of a magnesiumalkoxide of the formula M(OR)₂ wherein M is magnesium, O is oxygen and Ris a hydrocarbyl having from 1 to 20 carbons atoms, and a halogenatingagent; (2) an electron donor wherein the electron donor is diethylphthalate or di-isobutyl phthalate; (3) a titanating agent; b)contacting the catalyst component with an organoaluminum cocatalystcompound; c) contacting the catalyst component withdicyclopentyldimethoxysilane as an external electron donor simultaneouswith or after contacting the catalyst component with the organoaluminumcompound.
 2. The process of claim 1 wherein the magnesium alkoxide ismagnesium ethoxide.
 3. The process of claim 2 wherein the ratio ofelectron donor to magnesium ethoxide is 0.1 mmole phthalate/g Mg(OEt)₂to 0.2 mmole phthalate/g Mg(OET)₂.
 4. The process of claim 1 wherein thehalogenating agent is a Group III, Group IV or Group V halide.
 5. Theprocess of claim 4 wherein the halogenating agent is titaniumtetrachloride.
 6. The process of claim 1 wherein in step (a) the moleratio of magnesium alkoxide to halogenating agent is in the range ofabout 6:1 to about 1:3.
 7. The process of claim 6 wherein the mole ratioof magnesium alkoxide to halogenating agent is in the range of about 3:1to about 1:2.
 8. The process of claim 7 wherein the mole ratio magnesiumalkoxide to halogenating agent is in the range of about 2:1 to about1:2.
 9. The process of claim 1 wherein the titanating agent is atetra-substituted titanium compound with all four substituents being thesame and the substituents being a halide or an alkoxide or phenoxidewith 2 to 10 carbon atoms.
 10. The process of claim 9 wherein thetitanating agent is titanium tetrachloride.
 11. The process of claim 10wherein the amount of titanium tetrachloride in step (c) is in the rangeof about 0.5 to about 5 equivalents based on the magnesium alkoxide. 12.The process of claim 11 wherein the amount of titanium tetrachloride instep c is in the range of about 1 to about 4 equivalents.
 13. Theprocess of claim 12 wherein the amount of titanium tetrachloride in step(c) is in the range of about 1.5 to about 2.5 equivalents.
 14. Theprocess of claim 1 wherein the reaction product of (a) is in ahydrocarbon solvent.
 15. The process of claim 14 wherein the hydrocarbonsolvent is toluene, heptane, hexane or octane.
 16. The catalystcomponent of claim 15 wherein the hydrocarbon solvent is toluene. 17.The process of claim 1 wherein the cocatalyst is of the general formulaAlR'₃ where R' is an alkyl of from 1-8 carbon atoms or a halogen and R'may be the same or different with at least one R' being an alkyl. 18.The process of claim 17 wherein the cocatalyst is triethylaluminum. 19.A process of making a catalyst comprising:a) selecting a catalystcomponent for the polymerization of propylene wherein the catalystcomponent comprises:(1) the reaction product of magnesium ethoxide and ahalogenating agent; (2) an electron donor wherein the electron donor isdiethyl phthalate or di-isobutyl phthalate and wherein the ratio ofelectron donor to magnesium ethoxide is 0.1 mmole phthalate/g Mg(OEt)₂to 0.2 mmole phthalate/g Mg(OEt)₂ ; (3) a titanating agent; b)contacting the catalyst component with an organoaluminum cocatalystcompound; c) contacting the catalyst component with an external electrondonor simultaneous with or after contacting the catalyst component withthe organoaluminum compound wherein the external electron donor isdicyclopentyldimethoxysilane or cyclohexylmethyldimethoxysilane.
 20. Theprocess of claim 19 wherein the halogenating agent is a Group III, GroupIV or Group V halide.
 21. The process of claim 20 wherein thehalogenating agent is titanium tetrachloride.
 22. The process of claim19 wherein the titanating agent is a tetra-substituted titanium compoundwith all four substituents being the same and the substituents being ahalide or an alkoxide or phenoxide with 2 to 10 carbon atoms.
 23. Theprocess of claim 22 wherein the titanating agent is titaniumtetrachloride.
 24. The process of claim 19 wherein the reaction productof (a) is in a hydrocarbon solvent.
 25. The process of claim 24 whereinthe hydrocarbon solvent is toluene, heptane, hexane or octane.
 26. Thecatalyst component of claim 25 wherein the hydrocarbon solvent istoluene.
 27. The process of claim 19 wherein the cocatalyst is of thegeneral formula AlR'₃ where R' is an alkyl of from 1-8 carbon atoms or ahalogen and R' may be the same or different with at least one R' beingan alkyl.
 28. The process of claim 27 wherein the cocatalyst istriethylaluminum.